Search

Studies of the pantophysin ( Pan I*) locus in Atlantic cod and other marine gadoids indicate that the locus is under positive selection; in Atlantic cod, genotypic variation at this locus has been linked to differences in growth. Here, we present preliminary data comparing the growth and condition of different Atlantic cod Pan I* genotypes within families held under seminatural mesocosm conditions. Larvae from three full-sibling families carrying Pan I*bb or Pan I*ab genotypes were reared for 10 weeks in two mesocosms. Multivariate analysis of variance indicated that larvae carrying the Pan I*ab genotype exhibited significantly higher standard length, dry weight, and RNA: DNA ratio (condition factor) than did larvae that carried the Pan I*bb genotype, potentially indicating selection. The influence of linked loci cannot be excluded; indeed, the absence of a significant correlation between genotype and growth in one family may substantiate this. The lack of differences in survival among genotypes indicates that moderate selective effects are acting primarily through size-specific mortality and fecundity. The proposed putative fitness effects, together with documented marked geographic differentiation in the wild, have implications for Atlantic cod population structure, effective migration rates, recruitment, and local adaptation, which are of particular relevance in a species threatened by continuing exploitation and rising sea temperatures. [ABSTRACT FROM AUTHOR]

Examines the method for polymerase chain reaction (PCR)-based isolation of microsatellite arrays (PIMA). Use of PCR-based methodologies to isolate several kinds of genomic components; Assessment of the utility of PIMA; Advantage of the combination of random amplified polymorphic DNA enrichment and repeat-specific PCR isolation.

Examines the nondestructive technique for the recovery of DNA from dried fish otoliths for subsequent molecular genetic analysis. Utilization of otoliths for molecular genetic analyses; Procedure for extracting DNA from the surface of intact otoliths; Presence of recoverable DNA on the surface of the otoliths.

Understanding the historical emergence and growth of long-range fisheries can provide fundamental insights into the timing of ecological impacts and the development of coastal communities during the last millennium. Whole-genome sequencing approaches can improve such understanding by determining the origin of archaeological fish specimens that may have been obtained from historic trade or distant water. Here, we used genome-wide data to individually infer the biological source of 37 ancient Atlantic cod specimens ( ca 1050-1950 CE) from England and Spain. Our findings provide novel genetic evidence that eleventh- to twelfth-century specimens from London were predominantly obtained from nearby populations, while thirteenth- to fourteenth-century specimens were derived from distant sources. Our results further suggest that Icelandic cod was indeed exported to London earlier than previously reported. Our observations confirm the chronology and geography of the trans-Atlantic cod trade from Newfoundland to Spain starting by the early sixteenth century. Our findings demonstrate the utility of whole-genome sequencing and ancient DNA approaches to describe the globalization of marine fisheries and increase our understanding regarding the extent of the North Atlantic fish trade and long-range fisheries in medieval and early modern times.